Implemented ADT (Algebraic Data Type) for enum

[gdotdesign]

This PR makes it possible parameterize enums and it's options and destructuring them in case statements.

Here is the Mint only implementation of the Result type as an Enum:

/* The enum has two parameters. */
enum Result(error, value) {
  Error(error)
  Ok(value)
}

module Result {
  fun withDefault(value : b, result : Result(a, b)) : b {
    case (result) {
      /* We can get values from options like this. */
      Result::Ok value => value
      Result::Error => value
    }
  }
}

This allows for better data modeling and creating better state machines.